1. Field of the Invention
This invention relates to an underground continuous impervious wall and a method for installing the same and, more particularly, to an underground continuous impervious wall obtained by disposing an impervious sheet in a gutter, charging a hardening material on the opposite surfaces of the sheet and hardening the same and a method for efficiently installing the same.
2. Description of the Prior Art
For blocking underground spring water during construction of an underground building or blocking underground water in dam construction works, it has been in practice to construct an underground continuous wall or driving sheet piles and charging a seaming material at the joints.
When such prior art processes are carried out for the purpose of blocking water, there are the following problems.
(a) Underground continuous walls are usually formed such that they have thicknesses more than necessary. Therefore, unnecessarily elabolate works have to be carried out, and also a large quantity of extra concrete has to be used, thus increasing the installation cost.
(b) The process of driving the sheet piles and charging the seaming material at the joints also requires elabolate works and high material cost.
(c) It may be thought to form an underground continuous wall having a reduced thickness to reduce the cost of installation. However, there is no machine for excavating a narrow gutter. Even if such narrow gutter could be excavated, the fluidity of concrete would be spoilt to disable completion of a homogeneous underground wall.
(d) In view of the reliability of water-blocking, concrete walls are subject to formation of cracks at the time of earthquake, thus spoiling the water-blocking property. In the process using precast concrete panels or sheet piles, foreign materials, e.g., bentonite, are trapped so that it is impossible to obtain the sufficient water-blocking property.
An object of the present invention is to provide an underground continuous impervious wall, which can be readily installed, requires inexpensive installation cost and permits construction of an impervious wall having a highly reliable water-blocking property, and a method for installing the same.